Oieotjits of feinting telegeapes



(No Model.) I

s. D. FIELD. MEANS FOR GONTROLLING PRINTING GIRGUITS 01E PRINTING TELEGRAPHS.

No. 290,556. Patented Dec. 18, 1883.

WITNESSES NITED STATES STEPHEN D. FIELD, OF NEYV YORK, N. Y., ASSIGNOR TO THE COMMERCIAL TELEGRAM COMPANY, OF SAME PLACE.

MEANS FOR CONTROLLING PRINTING-CIRCUITS OF PRlNTING-TELEGRAPHS.

SPECIFIGATION forming part of Letters Patent No. 290,556, dated December 18, 1883.

Application filed August 6, 1883. (No model.)

V the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

In operating the ordinary printing-(cle graphs it is well known that in order to attain the highest speed an instrument is capable of the printing should be eiifected by as momentary a current as will charge the printing-magnet, and the printingarmature should leave its magnet promptly upon the cessation of the current, so that the platen or press may be immediately withdrawn from the type-wheel and not impede its revolution. In single-line printing-telegraphs this immediate movement of the platen away from the wheel is secured by the very conditions of the instrument, as in such the printing is ordinarily effected by an abnormal condition of currentan increase or reversal, for instance-and the abnormal condition is immediately changed to the normal condition.

In two-line printers as hitherto constructed and arranged it has not been possible to eiie'ct the printing by what may be termed a mere momentary flash of current. The result has been, therefore, that the printing armature has clung or stuck to its magnet longer than necessary for the accomplishment of the printing, thereby delaying the positioning of the type-wheel or type-wheels for the next print ing. The object of my invention is to remedy this, providing means in the transmitter controlling a two'wheel printer, or a series thereof, for controlling the type-wheel magnets, and for automatically throwing into the printingcircuit a flash of current effecting the printing, the circuit of which is immediately and automatically broken. To accomplish this, I use an ordinary transmitter having an arm attached to the shaft of an escape-wheel driven by any suitable power, and sending into the vmain circuit so long as in motion the pulsations for controlling the magnets operating the type-wheels. These pulsations may be intermittent of one polarity, or they may be reversals of polarity. A range of keys is provided normally out of the path of the rotating arm, but adapted to be placed in its path, 5 5

and thereby arrest its motion, stopping the pulsations of whatever character used, holding, consequently, the typewheel positioned by the last pulsation for the act of printing. The printing-circuit is controlled by a local relay-circuit, controlled in turn by this transmitter. The local relay-circuit embraces a local-relay battery, one pole of which is connected to the rotating arm of the transmitter and the other to the range of keys before noted, and two relay-magnets, the first closing the main printing-circuit, the second closing a shunt of the local relay-circuit around the first relay. The result of this is that whenever the rotation of the arm is stopped by the depression of a key the local circuit is immediately closed, the first relay closing the main printing-circuit and throwing the printingcurrent to line. The second relay, however, at the same instant closes the local shunt around the first relay, which is thereby rendered inactive, its armature fallin away and breaking the main printing-circuit. Thus, no matter what delay or stoppage of the rotating arm, or what may be the slowness of the operators, the printing-eirunit is closed but momentarily-the least possible interval of time necessary to effect the printing-and the printing-magnets are charged so briefly that they readily discharge and do not delay the operations of the escapement-magnets. This may be better understood by reference to the drawing, which represents, mainly diagrammatically, an arrangement embodying my invention.

Tr is the transmitter, having one or more ranges of finger-keys, A B O D, arranged on depression to project into the path of and stop an arm, F, on the axis of the escapewheel E, driven by any suitable motor, and rocking or operating the anchor P, which is the lever-key of a reverser, Re Be, one side of which is connected to the pole of any source of current, say, a battery, E B, the other side being con nected to the pole, while the anchor is connected to the ground Gr. While here shown as a reversing-transmitter, it is evident that a transmitter sending currents of one polarity only might be used. So long as F is permitted to rotate it follows that pulsations, either intermittent or reversed, will be sent over the line 1 1 to the escapement-magnets E M of a printing-telegraph, causing such magnets to control and position any suitable type-wheel or type-wheels. Of this printing-telegraph P M are the printing-magnets in the circuit of a source of current P B, controlled, as shown, by a relay-magnet, R, which is in a local circuit, 3 4, having a local battery, L B. One end of this local circuit goes to the aXis of the arm F, while the other, after passing through the relays R R, is connected to all the keys, as shown by the dotted line 4. If, now, F be stopped by any of the keys, owing to its depression, the local circuit 3 4t willbe closed, the armature-lever r of R attracted, and the main printing-circuit closed, the magnet P M being arranged to operate, and that immediately, upon the first flash of current. If, however, the operator be tardy or slow, this'closure is prolonged, and P M becomes so highly charged that it takes an appreciable interval for it to discharge and allow its armature to be retracted, the rotation of the type-wheels would be interfered with. To guard against such prolonged closure of the printing-circuit, a second relay, R, is placed in the local circuit 3 4. The armature-lever r and front stop of this relay control a shunt-circuit around the relay R, practically cutting it out of circuit. \Vhenever, now, the local circuit 3 at is closed, the armature-lever r of R closes the main printing-circuit at the same moment 1 closes the shunt around R, whose armature-lever immediately falls away. Thus, no matter how long the local circuit may be closed by the contact of E and a key,the printing-circuit is only momentarily closed and a single flash transmitted to effect the printing, the printing-magnets P M hence never becoming overcharged or needing time for discharge.

Having thus described my invention,what I claim, and desire to secure by Letters Patent, 1s

1. The combination, with a transmitter and a circuit for printing, of two relay-magnets, both in a local circuit controlled by the transmitter, one controlling the printing-circuit, the second controlling a shunt-circuit around the first, substantially as set forth.

2. The combination, with a transmitter controlling the escapement or type wheel circuit, of a local circuit, and two relays therein, one controlling the printing circuit, the second controlling a shunt to the first, so as to permit the first to close only momentarily the printing circuit, substantially as set forth.

3. The combination of two relay-magnets in one circuit, a main circuit controlled by the first and a shunt-circuit around the first controlled by the second, so as to limit the control of the main circuit by the first relay, substantially as set forth.

This specification signed and witnessed this 1st day of August, 1883.

STEPHEN D. FIELD.

Witnesses:

WM. B. W001), L. A. MCCARTHY. 

